1. Field of the Invention
This invention pertains to land vehicles generally, and more particularly to wheeled vehicles which are stable when loading and traveling, and which are propelled by an attendant. More particularly, the present invention pertains to vehicles that are sufficiently stable and safe for a single person to load and transport a wide variety of otherwise oversized or awkward cargo.
2. Description of the Related Art
Transport of large or oversized loads has typically presented challenges for people in many diverse industries. In schools and businesses, large tables and blackboards must occasionally be transported, either at the time of purchase and placement, or to accommodate various special events. This has typically required a large number of persons to each lift a part of the load. Unfortunately, if a person should accidentally trip, one or more of the persons may be seriously injured and the load may also be damaged.
In manufacturing, large or oversize sheets, panels, plates and the like must be moved about. In construction, various sheets, panels and construction modules need moved. Even in the furniture industry, mattresses must be moved about. Regardless of the industry, the handling of these large, typically very awkward, and sometimes heavy loads has been difficult. The use of more people to move these loads is generally unsafe, as aforementioned, and other approaches have long been desired.
In some industries, such as manufacturing, a forklift may be available to assist a person with the transport of a large load. The forklift is designed to support relatively large and heavy loads. Unfortunately, a forklift also requires special operator training, a substantial amount of space to move about, provides no cushioning for the load being transported, no tactile feedback for the operator in the event an obstacle or hindrance is encountered, and the lift is very expensive to purchase and operate. Consequently, the operation of a forklift generally is limited to those situations where cargo is delivered in shipping packages or the like or is durable enough to withstand heavy handling, and also where the cargo is being moved frequently enough to justify the cost of the machine and trained operator.
Where a forklift is not appropriate or available, hand trucks, rolling carts or the like have been used. The two-wheel hand truck or “dolly” is well known for transporting loads, and has been provided with various features to assist with particular loads. While the two-wheel hand truck is of tremendous help in transporting objects which are close in size to the hand truck, loads which are much larger are very difficult and often unsafe to carry. This stems from several limitations of the hand truck. First, the hand truck is balanced upon only two wheels. When a load is much larger than the toe of the hand truck, it is difficult for an operator to exactly balance at the midpoint of the load. Consequently, the load will all too often be slightly off-balance, which causes the hand truck to tend to wander or veer off course when being moved. Furthermore, the hand truck may also be relatively difficult to balance in a transport position, since the distance between the hand truck toe and operator hand may be relatively small compared to the overall height of the load. In this case, a great deal of operator strength may be required just to balance the hand truck about the axle of the two wheels.
The use of various carts and tables has also been proposed, and proves effective for the transport of relatively smaller loads, particularly where the load is comprised of many smaller packages. A single operator can then stack the smaller packages onto the cart or table, and then roll the table with load to a new location. The table or cart has the distinct advantage of not requiring an operator to balance the load. Once the load is placed upon the cart, the cart may be left stationary with no operator even present. Unfortunately, with a table or cart, the load most generally must be supported in a horizontal plane. Large planar or sheet-type material such as the aforementioned building sheets, mattresses or the like are often large enough to be difficult to load and handle when transported horizontally. Other carts have been constructed that enable large loads to be transported in a vertical plane. Unfortunately, there is no mechanism provided for loading the cart, and so the placement of the load upon the cart still requires the assistance of either more persons or forklifts or the like. Consequently, there has long been a need for a transport which overcomes the limitations of the prior art.